PKOPAGATION AND DISTRIBUTION OF FOOD FISHES, 1922. 75 



Because of the large demand for the pond fishes in this vicinity 

 repeated efforts have been made to pro23an;ate the large-mouthed 

 and small-mouthed black basses and other similar species. Climatic 

 conditions appear to be the main barrier to success in such work. 

 Frequent and sudden fluctuations in both air and water temperatures 

 incident to the rather high elevation result each season in a very 

 considerable loss of both eggs and young fish. During the fiscal year 

 1922 the results attained from the propagation of the so-called pond 

 fishes were more successful than usual, though not altogether satis- 

 factory. Seventy adult small-mouthed black bass produced 40,000 

 fry and fingerling fish. The large-mouthed black bass made a much 

 better showing, the nesting of 23 brood fish resulting in approxi- 

 mately 66,000 small fish for distribution. The crappie failed en- 

 tirely to reproduce, while 125 adult sunfish produced some 16,600 

 fingerlings. The brood stock of rock bass, 140 in number, appeared 

 to be in excellent condition and a fair number of young were ex- 

 pected, but only 5,000 were available at the distribution period. 



WYTHEVILLE (VA.) STATION. 

 [G. A. Seagle, Superintendent.] 



During the extended spawning period — October 13 to March 31 — 

 732,500 rainbow-trout eggs were obtained from the brood stock, 

 w^hich consisted of 3,300 female fish, about one-third of the number 

 being 2-year-old fish at their first spawning. Approximately 463,000 

 of the eggs were retained at the station for incubation, and 90 per 

 cent of them produced fry ; the remainder were shipped to A^arious 

 States and foreign governments and to other stations of the bureau. 

 Tlie brook trout distributed from this station were produced from 

 100,000 eggs that were acquired by purchase and incubated with but 

 a nominal loss. In the early spring, however, the fingerlings suffered 

 a heavy mortality, and but 53,000 were available for applicants. 



The year's work with the pond fishes represents a fair average of 

 the work of the past few seasons, although it is far from satisfactory, 

 and it is hoped that certain changes instituted during the year in 

 the water-supply system and drainage and along other lines will 

 effect a material increase in the output for the next fiscal year. The 

 more important improvements included a new settling tank and 

 filter and the completion of the nursery building mentioned in the 

 report for the fiscal year 1921. 



After heavy rains the spring water at Wytheville becomes very 

 turbid, owing to the seepage of surface water into the spring source. 

 This water when coming at certain stages of development of the 

 brook-trout fry causes serious losses, and during the spring of 1921 

 practically the entire stock of brook trout was lost. The effect on 

 the rainbow trout has not been so serious. To overcome this diffi- 

 culty of turbid water, a concrete settling tank was constructed, ap- 

 proximately 20 feet wide by 70 feet long, with a cement partition 

 extending longitudinally through the center to a point near one end. 

 This makes it necessary for the water to flow approximately 140 

 feet, after which it eixters a sand filter having a surface area of 80 

 square feet. 



